The pH metres are crucial instruments for various jobs since it comprises three components: a pH probe, an electrode, and high input impedance metre and when used appropriately, they may make a significant impact. On the other hand, pH metres are significantly more picky than our reliable thermometers. A pH metre requires regular maintenance and attention to ensure that it performs effectively.

How to Measure pH?

It is possible to acquire an approximate estimate of the pH level using pH sheets or indicators, which change colour as the pH level fluctuates. They have limits in terms of accuracy and might be difficult to read accurately in colourful or unclear samples due to the dyes used. A digital pH metre provides more precise pH measurements than a traditional one. It comprises three components:

  • A pH probe
  • An electrode for reference pH measurement
  • A high input impedance metre with the high input impedance

The pH electrode can be regarded as the battery voltage that swings in reaction to the pH of the solution under investigation. With the pH probe, you can measure the concentration of hydrogen ions within and outside a glass bulb, which produces a millivolt output proportional to the difference in relative hydrogen ion concentration inside and outside the bulb.

Common Mistakes to Avoid With pH Metre

The following are the common mistakes you notice when using pH metres and orp probes and how to avoid them.

Make sure you remove the caps.

Caps are used to protect and maintain the hydration of the electrode on each metre. The bigger cap prevents objects from being knocked around, while the smaller cap protects and strengthens the hydration of the electrode. Both must be removed for the metre to work properly. We commonly receive calls from consumers who have merely removed the first cover from their pH metre and are baffled as to why their pH metre has stopped working.

Wrong temperature testing

The temperature affects the pH of water. When the temperature is raised, the pH lowers, increasing acidity. While the mechanics of that idea are complex, your implications are not quite as complicated as they appear. Your sample must be measured at the same temperature as your buffering solutions to obtain an accurate measurement of it. If you calibrate at room temperature, you must measure at room temperature, which means that the ideal procedure is to take a tiny sample and quickly chill it to ambient temperature before testing. You may experience considerable fluctuations in the pH of the water in this case.

Leaving the electrodes dirty

pH testing with an orp probe can be a messy endeavour. Sticking the electrode in boiling milk, fermenting wine, or damp soil can result in an unnoticeable accumulation on the electrode’s surface. Fats, carbohydrates, and minerals can build up on the electrode, causing it to read slower or even incorrectly.

Cleaning your electrodes with a pH electrode cleaning solution will help to guarantee that they are clean. The cleaning solution is pH-balanced for the electrode and is an excellent technique to ensure that you always obtain accurate and quick readings. To ensure that your electrodes last as long as possible, apply the cleaning solution every time you use your metre.

Stored in water

The use of deionized water to store the electrodes of pH metres is another typical error that people make while using pH metres. While this appears to be a good idea for keeping the electrode wet, it might accelerate the degradation of your electrode.

In some instances, it is conceivable that ions will escape from the glass to form an ionic solution inside the water, resulting in higher equilibrium due to the ionic nature of the electrode glass itself. However, this is not always the case. When ions escape from the glass and into the liquid, the glass is deprived of its pH-probe properties, rendering the electrode ineffective. When storing your pH metre, you must use a pH-electrode storage solution to ensure that it is kept properly. The storage solution is hydrating and has the right amount of the right ions in the right places.


In addition to being wonderful tools, pH metres may also help you take your brewing, cheese-making, sushi-making, and even gardening skills to the next level. The best way to extend the life of your pH metre is to follow best practises. These include keeping your electrodes well-hydrated, using calibration buffer solutions, and controlling the temperature at which you conduct your tests to ensure that you get the longest possible lifespan out of your metre.